How the naval mine gave St. Petersburg breathing space

Jan 01 2015

Alexander Vershinin

specially for RIR

Russia's Navy prepares for practical training in laying of mines in 1912. Source: Open source

In the Crimean War of 1854-55, with Anglo-French naval forces massing against Russia and threatening the capital St. Petersburg, the Russians came up with an ingenious way of protecting the Baltic port, becoming the first in the modern era to employ floating mines.

It is the year 1854. Russia is locked in conflict with a strong
coalition of European countries and comes under pressure across the length and
breadth of its territory.In Crimea,
Sevastopol comes under heavy siege, while Anglo-French forces attempt to storm
Petropavlovsk-Kamchatsky in the Far East and bombard the northern port of Arkhangelsk.

The capital St.
Petersburg will be next – unless the Tsar’s overstretched fleet can throw up an
effective defensive shield around Russia’s "Window to Europe".

As the threat
grows from a powerful British naval squadron, a German-born physicist working
with the Russian Academy of Sciences, Moritz Hermann von Jacobi, receives orders
from the top to prepare a new secret weapon.

While early
forms of naval mines had been used by the Chinese since ancient times, this
weapon only became known in Europe in the 16th-17th centuries. But the main drawback
with early prototypes was their indiscriminate destruction of any vessel once
set, friendly forces included.

Moritz Hermann von Jacobi. Source: Wikipedia.org

Russian
engineers hit on the solution in the early 19th century when they fitted mines
with electric detonators, using two simple contacts hooked up to a power source
on land. The contacts connected as a ship passed and the flowing volts would
trigger the explosive charge.

Jacobi also equipped
his mines with iron detonator cylinders housed in a wooden cask 28 inches cm tall
and 20 inches wide, containing 22-33 lbs of gunpowder. However, the first use
of such mines showed that the rudimentary design caused the gunpowder to grow
damp.

The engineer subsequently
modified the mine housing, adding an additional protective layer of copper and
increasing the explosive charge to 55 lbs of powder.

Mine-laying
in the Baltic Sea by St. Petersburg began in April 1854 with the placement of 100
units between two artillery emplacements that protected the city, separated by
a mile of open water.

The number of
charges in this first ever combined mine and artillery screen was increased in
June 1855. In little more than a year the entire eastern part of the Gulf of
Finland was set with almost 2,000 mines, 500 of which were built to Jacobi’s
design and another 1,500 under a similar project by Immanuel Nobel, son of the
Swedish engineer Alfred Nobel.

Setting the Nobel mines under the city of Kronstadt. Drawn by E. Nobel. Source: Open source

Four British
ships hit mines, but due to the small explosive charge, none were seriously
damaged. The mines still did their job, however, keeping the enemy at a good
distance from St Petersburg.

The commander
of the British squadron reported to London the difficulties posed by "infernal
devices" on the port's approaches.

During the Crimean War mines also
protected Russian ports in Finland, the mouth of the River Dvina near Arkhangelsk,
and the Dnieper Bay in the Black Sea and the Danube delta - a total of 3,000 devices
that helped to redress the balance of power between the opposing fleets.

Mine design was continually improved until
the end of the 19th century, demonstrated by increasing explosive power and
buoyancy, as well as the navy's technical ability to place them at the desired
depth.

In the Russo-Turkish war of 1877-78, the
Black Sea Fleet’s mining activity virtually paralyzed the activity of Turkish
warships.

Mines were
also used to great effect in the 1904-05 Russo-Japanese war, employing the new
technique of dropping them from conveyor belts mounted on small boats. Each
charge held 120 lbs of explosives, which was enough to send the largest ships
of the time to the seabed.

The Russian
forces laid more than 4,000 mines during the war, destroying 13 Japanese ships,
including two battleships.

Like the
British and French in the Crimean War, the Germans enjoyed overwhelming
superiority at sea in the First World War. The only way to protect St.
Petersburg was through the unprecedented mass mining of the Baltic Sea, where 35,000
mines were laid over three years.

The naval
command devised some ingenious ruses to protect the mining fleet. In November
1914, mine layers disguised as conventional light cruisers blocked the sea
lanes off the coast of Sweden with mines.

Involving the
construction of a decoy third smokestack on the vessels to replicate a
cruiser’s silhouette, the deception deterred enemy forces from pursuing what
they took for much faster vessels.